The present invention relates to a holder on which various cutters such as a hole cutter are mounted. The cutter holder supports, for example, a shank of the hole cutter.
Japanese Patent No. 2558054 discloses a cutter holder, which includes locking balls (7) for locking a cutter (6) on a support cylinder (1), a stopper body (2), and a valve body (11) of an oil valve. Numerals in parentheses are reference numerals in the above publication. A first spring (3) urges the stopper body (2) to support the locking balls (7) in an unlocked state. A second spring (13) urges the valve body (11) to prevent cutting oil from flowing out when the cutter (6) is not being used.
As described above, the cutter holder of the above publication includes the first spring (3) for supporting the locking balls (7) in the unlocked state and the second spring (13) for closing the oil valve separately. Thus, the structure of the cutter holder is complicated.